Polymers have become one of the most vitally used materials in the production of innumerable products of manufacture. However, polymeric materials have an important deficiency, that is, they are subject to ultraviolet and oxidative degradation which affects their aesthetic appearance. Degradation exhibits itself as a partial or total loss of structural integrity, discoloration of the product, loss of flexibility, or a combination of the above phenomena.
To protect polymeric materials from the undesirable degradation, a variety of stabilizers can be added to them. The most often used stabilizers are antioxidants, antiozonants, heat stabilizers and ultraviolet (UV) light stabilizers. More often, to afford maximum protection against all types of degradations, a mixture of stabilizers, such as for example antioxidants, and UV light stabilizers, are usually employed.
A variety of UV light stabilizers are known in the prior art such as benzoates, benzotriazoles, benzophenones, and more recently, hindered amine or piperidine type compounds. A rather extensive list of different piperidine type UV light stabilizers are listed in U.S. Pat. No. 4,049,647. However, all of the prior art piperidine type UV light stabilizers are of relatively low molecular weight. The present invention deals with nonpolymeric but high molecular weight piperidine compounds which are useful as UV light stabilizers.